Borehole measurements



July 5, 1966 BRYANT ETAL 3,258,963

BOREHOLE MEASUREMENTS FiledMarch 18. 1960 4 Sheets-Sheet 1 Harvey L. Bryant Inventors Millage M. White By Attorney y 1966 H. L- BRYANT ETAL 3,258,963

BOREHOLE MEASUREMENTS Filed March 18. 1960 4 Sheets-Sheet 3 GAMMA RAY FLOWMETER LOG ABSORPTION INTENSITY BPD DENSITY O 200 400 600 L0 .8 .6 .4 .2 O

FIG. 4

Harvey L. B.yont Inventors Millage M. White By% A9. M Attorney y 966 H. L. BRYANT ETAL 3,258,963

BOREHOLE MEASUREMENTS Filed March 18, 1960 4 Sheets-Sheet 4 IOOO SPINNER R.P.M.

BPD O IL OR WATEF Q (LE/DAY GAS I I l l FIG. 5

Harvey L. Bryant lnvemors Millage M. White By% W Ahorney United States Patent 3,258,963 BOREHOLE MEASUREMENTS Harvey L. Bryant, Tulsa, Okla, and Millage M. White,

Durango, Colo., assignors, by mesne assignments, to

Esso Production Research Company, Houston, Tex., a

corporation of Delaware Filed Mar. 18, 1960, Ser. No. 16,039 4 Claims. (Cl. 73-155) This invention relates to a system for determining flow of fluids from subsurface earth formations. More particularly, the invention refers to a system to locate the fluid entry points and to identify and measure the quantity of water, gas and oil produced from each section of a formation in a petroleum well.

To recover oil and/or gas from a subterranean reservoir, it is customary in the art of petroleum production to drill a borehole from the surface of the earth down to and through the reservoir rock. The well is then lined with casing and the casing is cemented within the borehole. The casing may extend through the producing formation, and if so, it is perforated to permit flow of fluid to enter in from the formation. In some instances, although not the general practice, casing is set only to the top of a producing formation in what is known as an openhole completion. After the casing has been set through an oil producing formation it is perforated at points opposite the oil producing zones so that oil is selectively produced as much as possible from the reservoir through the well. If the producing well is essentially a gas well the perforations are opposite the gas zones.

The oil produced from a cased well is not ordinarily conducted to the earths surface through the string of casing itself. Instead, a second string of pipe which is normally called tubing or production string is positioned within the well with its lower end generally spaced somewhat above the oil producing zone. If more than one reservoir zone is present, the oil from these Zones may be produced through one or more such production strings. In any event, the lower end of such production string is packed olf within the string of easing generally somewhat above its production zone. That is, the annular space between the production string and the casing is packed off or sealed.

Several methods of investigating the productivity of the different strata open to the well. bore have been used in the past. For example, the flowmeter such as described in US. Patent No. 2,856,006, issued to Buck et al., describes a flowmeter which may be used. That type flowmeter is able to detect the entry point and measure the quantity of fluid entering the well bore through each set of perforations. Unfortunately the instrument is incapable of differentiating between oil, water and gas. It is thus impossible to make an accurate and reliable production profile of a section in which oil is produced together with either water or gas or both. The system described herein shows an apparatus and a method by which an accurate production profile of a section of a producing zone may be made in which the quantity and the type of fluid entering the borehole at different points may be accurately detected and determined.

Briefly, this invention includes a well logging tool which comprises means for simultaneously measuring the density and rate of flow of fluid in a well bore. Briefly, a preferred well logging tool includes a body member having a passageway for flow of fluid therethrough, measuring means responsive to the quantity of fluid flowing through such passageway; a portion of the passageway is shielded against natural gamma radiation and a gamma ray source and a gamma ray counter means is mounted in spaced relationship within the shielded portion of the passageway to detect the density of the fluid in the passageway. In

' for days :and even then may be unusable.

ice

operation, the logging procedure is conducted while the well is producing under flowing conditions.

lit is important that the density of the fluid flowing in the well bore be detected simultaneously with the measuring of its flow. It is known that a well flowing, even against a given back-pressure, will produce at varying rates. In some wells these rates of production vary considerably over a matter of a few hours :or less. In order to get the best possible correlation between the density and the rate of flow of the fluid being measured then it is most important that both measurements be made simultaneously. By obtaining these measurements at all depths on posite the penforations, an accurate study of the wells producing characteristics can then be deter-mined from this data. Detailed production characteristics to show variation of flow with time can be obtained by making additional such measurements at regular intervals.

It is noted that various indirect means or methods have been introduced in the art for making density determina-' tions of fluids in a borehole. Those methods include pressure recorders and samplers. None of these systems has found general acceptance in the industry for one reason or another. For example, the means of pressure determination are inaccurate and usually are not remote recording. It is practically impossible to obtain reliable density determination using pressure measurements as small errors present in pressure gauges, even less than one percent, renders the pressure data unusable for density determinations. Temperature surveys also have to be run and considered before the pressure data can be interpreted. Density data thus obtained may not be available Samplers, too, have their limitations, for example, they tend to be bulky and do not lend themselves to continuous logging. Samples have to be carefully analyzed in the laboratory with great care taken to allow for borehole conditions of temperature, pressure, etc. Analysis time may take days thus preventing immediate well remedial work. In the systemdisclosed in this application, the density of the fluid in a Well bore is determined accurately in \a direct manner simultaneously with the measurement of flow of fluid therein.

The nature and the objects of this invention will be readily apparent and more easily understood from the following description taken in conjunction with the drawings in which:

FIG. \1 is an elevation schematic view of the device of the present invention positioned in a well bore;

FIG. 2A and FIG. 2B show a sectional view from top to bottom of another embodiment of the invention with FIG. 2A illustrating the upper section and FIG. 2B illustrating the lower section;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2B;

FIG. 4 illustrates a flow and density profile of underground formation, and

FIG. 5 illustrates a calibration chart form.

FIG. 1 is a schematic diagram'of one embodiment showing the best mode contemplated for carrying out this invention. Tool 10 is suspended from the surface of the earth in a well bore 12 by a multiple conductor supporting cable 14. A suitable multiple conductor cable is commercially available from American Steel and .Wire, Division of United States Steel, Cleveland, Ohio. Well bore 12 is lined with casing 13. A tubing string 15 is suspended in the casing and the annular space between tubing 15 and casing 13 is sealed by packer 17. Multiple conductor cable 14 is passed over a pulley means 16 and passes on to control means 18 and record means 19. Control means 18 will not be discussed in detail but is of a nature to raise and lower tool I10 in the well bore as desired. Recording means :19 is of a character to continuously record the depth of the tool as well as the electrical signals received from the tool.

Tool includes a motor section 20, pump section 22 having fluid entry and draining slits 24, a sleeve packer 26, a fluid meter section 28 having spinner 30 and inlet ports 32 and nose cone 34. The detail of construction and operation of parts enumerated in this paragraph Wlll not be elaborated upon as they are fully described in the H. M. Bucket al. Patent No. 2,856,006. Suitable relay means can be provided to switch the conductor cable from motor to contacts of spinner section 30.

The gamma ray absorption logging tool includes a shield 38. Shield 38 is enclosed at each end except for inlet and outlet ports 40 at the lower end and fluid inlet and outlet ports 42 in its upper end. Shield 38 is made of a material substantially impervious to gamma rays. A suitable material, for example, is lead or tungsten. Gamma ray source 36 is positioned in the lower end of shield 38. The lead or equivalent material serves a dual purpose of concentrating gamma rays from source 36 to detector 44 and of preventing natural gamma radiation, that is, radiation from the formation surrounding a well bore from striking the detector.

Gamma ray source 36 may be any conventional source of low energy gamma radiation such as, for example, cesium 134 or cesium 137. Detector 44 may conveniently comprise a bundle of Geiger tubes, whose output is amplified by amplifier means 46 and transmitted through one lead of cable 14 to the surface of the earth.

Fluid outlet ports 42 are provided immediately below detector 44 and inlet ports 40 are adjacent gamma ray source 36. Thus, as tool 10 is raised within a well, well fluid tends to enter within space 48 through ports 40 and leaves space 48 through passage ports 42 when the tool is at a point in the well bore where the fluid flow is upwardly. If the tool is at a point in the Well bore where fluid flow is downwardly, fluid enters ports 42 and space 44 and leaves space 48 through ports 48.

In the operation of the tool in FIG. 1, tool 10 is normally lowered to the bottom of the formation or section of the earth to be tested. The tool is then slowly raised, being stopped at all desired depths while flow and density are measured. While making measurements in this manner, the packer 26 is fully inflatedto form a complete seal between the tool 10 and the casing 13, thus diverting all flow, at that depth, through the packer mandrel. In a preferred operation, packer 26 is only partly inflated so that tool 10 can be moved without rupturing the packer. Preferably, centralizers 27 are provided to hold the tool in the center of the hole to insure even inflation of the packer so that any bypass of fluid around the packer will be evenly distributed around the periphery of the packer. When packer 26 is partially inflated and the tool pulled slowly uphole at a constant rate; flow, density, and depth measurements are simultaneously made and recorded continuously across the perforated interval. Although some of the fluid may bypass the packer since it does not form a complete seal while operating in this manner, the amount of bypass will remain in proportion to the rate of flow through the tool. Since the total volume of production from a well will be measured at the surface, the amount of bypass can be calculated. With the packer partially inflated, essentially all of the fluid flow in the well bore is directed through inlet ports 32, through the fluid meter section 28,.ports 40, space 48 and out ports 42. Therefore, essentially all of the fluid passes through spinner section 28. The greater the flow of fluid the more rapid is the rotation of spinner 30. As described in Patent No. 2,856,006 supra, the rotation of spinner is detected and is recorded at the surface in terms of barrels per day, for example. The spinner 30 actuates a coded signal which can discriminate at the surface whether this spinner is going clockwise or counter-clockwise. Thus, giving information as to whether fluid is flowing upwardly or downwardly through fluid meter section 28 at any position or positions of the tool.

As fluid flows upwardly through ports 40 into space 48 the amount of gamma radiation absorbed by gamma ray detector 44 will depend upon the density of the fluid flowing through space 48. Water will have one density; oil, another; and gas, a third. The density of the fluid flowing through space 48 is determined quickly and accurately in a direct manner by measuring changes in the amount of gamma ray absorption. The density of the fluid flowing through the tool is a function of the intensity recorded by the gamma ray detector. This is expressed in the equation Z=KI efi1 in which I=intensity recorded, I =source intensity, e=2.71828, a=absorption coeflicient, t=spacing between source and detector, and K: instrument constant. Construction of the tool is such that all of the quantities in the above equation are known except the absorption coeflicient. The absorption coeflicient is proportional to the density of the fluid flowing in the tool. By recording the absorption coefficient on a calibrated chart, density is directly determined. As will be seen, when FIG. 4 is discussed in detail, by knowing the density and the flow rate it is possible to determine accurately not only the volume of flow but the fluid which is flowing into the well bore at various points along the interval being surveyed.

Attention will now be directed to FIGS. 2A and 2B which shows another embodiment of the apparatus of this invention. This illustrated tool has a housing which is divided conveniently into an upper section 50, an intermediate section 52 and a lower section 54. Centralizers 56 are secured to the housing to position the tool in the center of the casing. Only one such centralizer is illustrated although any desired number may be used.

Mounted in the upper housing section 50 is a fluid density determination section. It includes a cylindrical member which may be upper section 50 made of a suitable material, for example, lead. The lead or equivalent material serves a dual purpose of concentrating gamma rays from source 58 to detector 69 and preventing natural gamma radiation from striking the detector. The ends of the lead member are enclosed with lead or other suitable material substantially impervious to gamma rays. In this instance, a plug 62 closes the lower end and a cap means 64 encloses the upper end. A gamma ray source is positioned on and supported from plug 62. A gamma ray detector 68 is placed in the upper section opposite gamma ray source 58. Gamma ray source 58 is similar to gamma ray source 36 as explained in connection with FIG. 1 and gamma ray detector 69 is similar to gamma ray detector 44. Detector 60 is connected to pro-amplifier 66. Pre-amplifier 66 is connected with recording equipment not shown at the surface in FIG. 2A through one conduit of multiple conduit and support cable 68 which is a similar cable to cable 14 shown in FIG. 1. Cable 68 likewise supports the logging tool. Upper section 50 has lower ports 82 and upper ports 84 so that fluid may enter and leave the interior of upper section 50. Baflles or the like may be used to aid or promote such flow.

Mounted on intermediate section 52 of the housing is a motor 70 with shaft 72. Power for motor 70 is supplied through one conduit of multiple conduit cable 68. Lower housing section 54 is adapted to sealingly receive extension 74 of upper section 52 when lower section 54 is connected to intermediate section 52 by tightening of threads 76. Extension 74 rests on shoulder 78. Lower section 54 has a threaded bore below shoulder 78.

A driving member 86 has at its lower end external threads matching those of threaded bore 80. The upper end of driving member 86 is more or less a hollow mem- 'ber having spline 88. A ratchet section member 90 is connected to shaft 7-2 of motor 70 by coupling 92. The lower end of ratchet section 90 may be termed a guide shaft 94 and extends into bore 96 of driving member 85. Ratchet section 90 has thereon a first ratchet 98 and a second ratchet 100. Ratchet 98 is of a character to have a shoulder to engage the spline on clockwise rotation and ratchet 100 is of a character to engage the spline on counter-clockwise rotation. Spline 88 is of a vertical dimension to limit the vertical travel of driving member 86 as desired. When motor 70 is rotated in clockwise direc tion, first ratchet 98 engages spline 88 to drive member 86 dolwnwardly as it advances in threaded bore 80. When driving member 86 has advanced downwardly so that ratchet 98 no longer engages spline 88 the downward movement of driving member 86 is stopped and further clockwise rotation of motor 70 has no effect on driving member 86. When first ratchet 98 is beyond the upper end of spline 88, second ratchet 100 is in a position to engage spline 88 upon counter-clockwise rotation of shaft 72 of motor 70. Counter-clockwise rotation of shaft 72 causes the driving member 86 to rotate in a counter-clockwise direction thus raising driving member 86 until second ratchet 100 is no longer engaging spline 88. At this point, further counter-clockwise rotation of shaft 72 has no effect on driving member 86. As will be seen, this feature is used to advantage in the operation of the expandable spinner blades 102.

Attached to the lower end of lower section 54 is magnet housing 104. Magnet housing 104 is rotatably supported from lower section 54 of the housing by bearing means 106.

Supported from magnet housing 104 is a spinner support member 108. Spinner blades 102 are attached to spinner support member 108 at pivots 110. A splined shaft 112 is connected to driving member 86 by bearing means 114. Spline shaft 112 extends through a matching bore 116 in lower housing section 54, through bore 118 of magnet housing 104, bore 120 of rack gear sleeve 122 to nose plug 124 at the lower end of the tool. Rack gear sleeve 122 is rotatably supported from shaft 112 by bearing member 126. However, gear sleeve 122 is fixed longitudinally with shaft 112 by shoulder members 125 and 127. Pinion gears 128 are provided for spinner blades 102 about pivots 110. A rack section 130 is provided on the upper end of rack gear sleeve 122 and are arranged to mate with pinion gear 128.

Magnetic housing 104 has magnet 1 32 and counterbalance 134. As spinner blades 102 rotate, magnet housing 104 likewise rotates. Positioned in the lower portion of lower housing section 54 are three magnetic switches 1'36, 138 and 140 as shown particularly in FIG. 3. Each magnet switch has a bias magnet 142. Magnetic switch 136 has reed elements 144 and 146. Switch 138 has reed elements 148 and 150 and switch 140 has reed elements 152 and 154. Although the contacts of reed elements 144 and 146 are normally closed with magnet 132 in position shown, they are illustrated as being normally opened.

Magnetic housing 104 and magnet 132 are rotatable with respect to lower housing section 54 and magnetic switches 136, 138 and 140. As magnet 1132 rotates directly underneath switch 136, for example, the contacts of reed elements 144 and 146 are closed. Switches 136, 140 and 142 are connected through a lead in conduit supporting cable 68 to the surface of the earth to a recorder not shown at which the opening and the closing of the switches are recorded. It will be noted that switches 13 6, 138 and 140 are spaced such that one code is received for counter-clockwise rotation and another received for clockwise rotation. This permits it to be determined at the surface whether the fluid is flowing upor down by spinner blades 102.

Having described in detail the apparatus shown in FIGS. 2A, 2B and 3, it is believed that its operation is apparent. However, a brief description of its operation will now be given. The device is assembled essentially as shown in FIGS. 2A and 2B with the gamma ray source 58 being placed in the tool just prior to the time when it will be lowered into a well bore. Motor 70 has been counterclockwise rotated such that driving member 86 is in its upper position. When in this position, spinner blades 102 are in their retracted position; that is, they are lying flat along spinner support member 108. The device then is ready to be lowered into the tubing in a well bore. When the lower end of centralizer 56 contacts the tubing, centralizer 56 compresses against the housing and the tool slides through the tubing. 'When the tool passes through the lower end of the tubing the centralizer 56 expands against the casing of the borehole.

In the preferred manner of operation, the tool illustrated in FIGS. 2A and 2B, is lowered to the bottom of the section of the earth to be logged. As the tool moves out of the tubing, the compressed centralizers expand to touch the casing and hold .the tool in the center of the hole. When the tool has reached its lower position, motor 70 is driven in a clockwise position. Then ratchet 98 engages spline 88 and drives driving member 86 downwardly. This forces spline shaft 112 downwardly which also moves rack gear sleeve 122 downwardly. As rack gear 122 moves downwardly it drives pinion gears 128. This causes spinner blades 102 to pivot about pivots until the spinner blades are in a horizontal position. It will be noted that the pinion gear 128, rack section and the length of spline 88 are designed such that when spline 88 has moved downwardly such that ratchet 98 no longer engages spline 88, the spinner blades 102 are in a horizontal or expanded position and likewise when spline section 88 is moved upwardly such that ratchet 100 doe-s not engage spline 88, the spinner blades 102 are in a retracted position. After the spinner blades 102 have been expanded, the tool is raised slowly through the well bore. This tool will be run in a well during a period when the well is producing. The tool is pulled slowly upwardly in the borehole. The fluid which flows upwardly in the borehole causes spinner blades 102 to rotate. The rate of rotation is detected by magnetic switches 136, 138 and with the rate of contact being recorded at the surface. At the same time a portion of the fluid flows through ports 82 and out ports 84 through upper housing section 50. Gamma ray source 58 is continually emitting gamma rays and the amount of absorption and fluid density is reflected in the lever of gamma rays detected in detector 60-. The detection of gamma rays is pre-ampli-fied by pre-amplifier 66 and is transmitted to the surface of the earth through lead in cable 68 where it is recorded. After the interval has been logged, it is then desired to remove the tool from the well bore. To accomplish this, motor 70 is first counter-clockwise rotated thus raising driving member 86, spline shaft 112 and rack gear sleeve 122. Rack section 130 engages pinion gear 128 and spinner blades 102 are pivoted to their retracted position. The tool is then retrieved through a tubing string to the surface.

Attention will be now directed especially toward FIG. 4 which illustrates a flow and density profile of an underground formation. The section of the earth to be logged has been penetrated by a borehole 154 with tubing 156 set therein and a packer 158 set about the tubing. Also shown on FIG. 4 is flowmeter log showing the barrels per day flow of fluid along the interval logged and a density log showing the density of the flowing fluid. The vertical scale of the well bore, the hole flowing log, and the density log are the same. For the purpose of illustration it is assumed that the water has a density of 1, the oil is 30 API and has a density of .877, and the gas density is .091. It is assumed that casing lines borehole 158 and has perforations 161 in the lower part of sand 162, perforations 163 in the upper part of sand 162, perforations 164 in sand 165, lower perforations 166 and upper perforations 167 in sand 168. The logging tool starts its logging at the bottom of the well bore. The water below sand 162 is still not moving except for the slight turbulence as the logging tool is slowly pulled upwardly through the water. The flowmeter log then logs or records zero barrels per day unit it reaches the lower portion of sand 162 through perforations 161 and the flow curve starts upwardly. It is known that the fluid coming in from the bottom portion of sand 162 is Water as the density curve has not varied from 1. When the logging tool is opposite perforations 163 there is an increase in flow from 100 to 150 barrels per day as indicated by the flowmeter log. It is known that this fluid entering perforations 163 is oil by a record recorded on the density log. The density log shows the density to change from 1.0 to 0.956. As 50 barrels of oil added to 100 barrels of water would cause this change of density, it is known then that the 50 barrels of fluid entering perforations 163 is oil.

As the logging tool is moved upward through the borehole opposite shale 170 there is no change in the flow in rate or the density as no fluid is entering that sec tion of the borehole. When the logging tool reaches perforations 164 in sand 165, the flowmeter log shows that there is 100 barrels per day increase in volume of fluid flowing through the tool. It is also recorded on the density log that the density of the fluid flowing in the borehole drops from .956 to .920 thus indicating the fluid entry to be oil. There is no change in the flowing record or the density record as the logging tool is raised through shale 171. When the tool reaches perforations 166 in sand 168, the fluid flow increases 50 barrels per day and the density decreases to .911 indicating the fluid entry to be oil. When the logging tool reaches perforations 167 in sand 168, the flow rate increases from 300 to 440 barrels per day. It is known that this increase in volume is due to gas being produced through perforations 167 as the density drops from .911 to .342. Only gas of .091 density could cause this great a drop in density. The borehole flow profile at points 175 and 176 can now be corrected to indicate 36,000 cubic feet per day of gas entry instead of the 140 barrels per day fluid entry. A convenient way to determine the amount of gas entering perforations 167 may be accomplished by the preparation of a spinner calibration chart shown in FIG. 5. In that figure, the coordinate represents the spinner r.p.m. and the abscissa either barrels per day of oil or water and cubic feet per day of gas. For a given means (1) and oil curve, (2) a water curve, and (3) a gas curve can be prepared either experimentally or by calculations. For example, in FIG. 5, 800 r.p.m. represents either 140 barrels per day of oil or 36,000 cubic feet of gas (density of 0.091). Without knowledge of the density of the fluid it would not be possible to determine whether the entry at perforations 167 is water, oil or gas. By knowing the magnitude of the density decrease it is known that the fluid entering perforations 167 is gas.

The logging technique illustrated above in regard to FIG. 4 in particular, is a very valuble technique. It shows not only where the fluid enters a borehole but the quantity and the nature of the fluid. For example, it shows that 100 barrels of water is entering perforations 161, 50 barrels of oil is entering perforations 163, 100 barrels per day of oil is entering perforations 165, 50 barrels of oil per day is entering perforations 166 and 36,000 cubic feet of gas per day is entering perforations 167. From the information obtained from this logging procedure, it is known that perforations 161 are productive of water only and therefore should be closed such as by a squeeze cementing job. It is also known that perforations 167 produced 36,000 cubic feet per day of gas. It is normally desired that the gas production be used as a means of driving the oil from the formation and should not be produced separately. It would, therefore, be desirable. to plug perforations 167.

While there are above desclised but a limited number of embodiments of this structure, process and product of the invention herein presented, it is possible to produce still other embodiments without departing from the inventive concept herein disclosed. It is therefore desired 8 that only such limitations be imposed on the appending claims as are stated therein.

What is claimed is:

1. A well logging tool for operation in the bore of a well which comprises in combination: a housing member; a motor mounted in said housing member operable from the surface; a shaft extending downwardly from said motor; a magnetic switch in the lower end of said housing; a magnet housing having a magnet therein rotatably supported from the lower end of said housing such that the rotation of said housing with respect to said magnetic switch gives off a signal responsive to such rotati-on; a spinner blade support member suspended from the lower end of said magnet housing in a nonrotatable relationship therewith; pivots mounted on said support member; a plurality of spinner blades pivotally attached to the pivots of said spinner blade support member; pinion gears on each said blade arranged about each pivot; a rack gear sleeve supported interior of said support member and having a rack section engaging said pinion gears; a second shaft extending through the lower end of said housing, said magnet housing and said rack gear member; means rotatably supporting said rack gear sleeve from said second shaft in a non-longitudinal relationship; a ratchet section means connecting the said shaft of said motor and the said second shaft and of a character to convert rotary motion of said first shaft into a first longitudinal motion of said second shaft and to convert counter rotation of said first shaft into a second longitudinal motion in a direction opposite from said first longitudinal motion; a multiple conduit cable for supporting said tool, said conduit having a lead for said magnetic switch and a lead for said motor.

2. An apparatus as defined in claim 1 including centralizers supported on the outer surface of said housing member.

3. An apparatus as defined in claim 1 in which said ratchet section means includes a threaded bore in said housing member; a driving member having threads mating with said threaded bore, one end of said driving member forming a cylinder with a vertical spline having limited vertical length upon the inner wall thereof; a first ratchet mounted on said shaft of said motor engageable with said vertical spline on clock'wise rotation; a second ratchet mounted on said shaft of said motor engageable with said vertical spline on counterclockwise rotation; the vertical length of said spline being the desired vertical travel of said second shaft; and bearing means rotatably attaching said driving member to said second shaft in a manner to have common vertical movement.

4. A well logging tool which comprises in combination: a body member having an upper portion and a lower portion, said body member adapted to be movable within a well bore; means rotatably attaching said upper and said lower portions; a shaft supported from said extending downwardly from the upper portion to the lower portion of said body member; means for moving said shaft longitudinally with respect to said body member; pivots supported by said lower portion; spinner blades mounted on said pivots; means for extending said spinner blades into a horizontal position into the path of flow of fluid within the well bore upon one longitudinal movement of said shaft with respect to said body member, such that the spinner blades are rotatably responsive to the rate of flow of fluid in the well bore, said means for extending said spinner blades also being operative for retracting said spinner blades upon the opposite longitudinal movement of said shaft with respect to said body member; and means indicating a rotation of said spinner blades with respect to said upper portion of said body member.

(References on following page) 0 10 References Citfed by the Examiner 2,965,753 12/1960 Reynolds et a1. 73155 X UNITED STATES PATENTS 3,036,460 5/1962 Wh1te ed: 01 73 155 8/1952 L 73 155 FOREIGN PATENTS 21116 1/1957 Rumble et a1. 73-155 5 6/1923 Germany 3/1957 Wiley et a1. 73-155 LOUIS R. PRINCE, Primary Examiner. 9/1959 Buck ROBERT EVAINS, CHARLES A. CUTTING, RICH- 4/1960 Widmyer 73-155 X ARD c. QUEISSER, JOSEPH P. STRIZAK, 11/1960 Egan et a1. 250-435 10 Examiners- 1 2/1960 Rumble 73 -231 x H. R. PATTON, D. 0. WOODIEL, Assistant Examiners. 

4. A WELL LOGGING TOOL WHICH COMPRISES IN COMBINATION: A BODY MEMBER HAVING AN UPPER PORTION AND A LOWER PORTION, SAID BODY MEMBER ADAPTED TO BE MOVABLE WITHIN A WELL BORE; MEANS ROTATABLY ATTACHING SAID UPPER AND SAID LOWER PORTIONS; A SHAFT SUPPORTED FROM SAID EXTENDING DOWNWARDLY FROM THE UPPER PORTION TO THE LOWER PORTION OF SAID BODY MEMBER; MEANS FOR MOVING SAID SHAFT LONGITUDINALLY WITH RESPECT TO SAID BODY MEMBER; PIVOTS SUPPORTED BY SAID LOWER PORTION; SPINNER BLADES MOUNTED ON SAID PIVOTS; MEANS FOR EXTENDING SAID SPINNER BLADES INTO A HORIZONTAL POSITION INTO THE PATH OF FLOW OF FLUID WITHIN THE WELL BORE UPON ONE LONGITUDINAL MOVEMENT OF SAID SHAFT WITH RESPECT TO SAID BODY MEMBER, SUCH THAT THE SPINNER BLADES ARE ROTATABLY RESPONSIVE TO THE RATE OF FLOW OF FLUID IN THE WELL BORE, SAID MEANS FOR EXTENDING SAID SPINNER BLADES ALSO BEING OPERATIVE FOR RETRACTING SAID SPINNER BLADES UPON THE OPPOSITE LON- 